How many pages does a printer have to print before it can be cancelled?

If a print job is cancelled before any data is transferred from the printer's queue to the printer's memory, no pages are printed. If it is cancelled after pages have been transferred to the printer's memory, those pages print even after you cancel the job.

Print jobs may be generated by different people and different programs and sent to be printed but are generally held in a print queue on the print server or the computer from which the item was generated if it is directly connected to the printer. Those items in the queue are transferred to the printer's memory once enough memory is available to do so.